During Dr. Posen's presidency, the Peterson Institute has won global recognition as the leading independent think tank in international economics, including repeated top rankings from the Prospect Think Tank Awards and the Global Go To Think Tank Index. Under his leadership, PIIE has expanded to include 42 world-renowned resident and nonresident fellows and increased its endowment by 50 percent. Since 2013, PIIE has developed high-level recognition and research partnerships in the People's Republic of China, while deepening longstanding ties with policymakers in other East Asian, European, and North American capitals. The Institute also has broken new ground in providing accessible economic analysis to the general public.

Posen has been the recipient of major grants and research fellowships from the American Academy in Berlin, the Brookings Institution, the Bank of England, the European Commission, the Ford Foundation, the Sloan Foundation, and the US National Science Foundation. In November 2018, he gave the inaugural Adam Smith Distinguished Lecture at the University of Glasgow. In January 2019, he was named a CEPR Distinguished Fellow. He served seven terms as a member of the Panel of Economic Advisers to the U.S. Congressional Budget Office from 2005 to 2019. Posen received his BA and PhD from Harvard University.

Posen has been widely cited and published commentary in leading news and policy publications, including the Financial Times, Foreign Affairs, New York Times, Wall Street Journal, Washington Post, Nihon Keizai Shimbun, Asahi Shimbun, Handelsblatt, Die Welt, Harvard Business Review, and The International Economy. He appears frequently on Bloomberg television and radio, among other media programming.